This review summarizes the state of knowledge about the major bacterial and viral pathogens of fish found in Turkey. It also considers diseases prevention and treatment. In this study, peer reviewed scientific articles, theses and dissertations, symposium proceedings, government records as well as recent books, which published between 1976 and 2013 were used as a source to compile dispersed literature. Bacterial and viral disease problems were investigated during this period in Turkey. Total of 48 pathogen bacteria and 5 virus species have been reported in Turkey. It does mean that all the bacteria and virus present in fish have been covered since every year new disease agents have been isolated. The highest outbreaks occurred in larval and juvenile stages of the fish. This article focused on geographical distribution, host range, and occurrence year of pathogenic bacteria and virus species. Vibriosis, Furunculosis, Motile Aeromonas Septicemia, Yersiniosis, Photobacteriosis and Flavobacteriosis are among the most frequently reported fish diseases. Meanwhile, Vagococcus salmoninarum, Renibacterium salmoninarum, Piscirickettsia salmonis and Pseudomonas luteola are rarely encountered pathogens and might be emerging disease problems. Finally, the current status in fish diseases prevention and their treatment strategies are also addressed.